Eels are one of the purest water creatures in the world, there is a high nutritional and medicinal value in them such as nourishing, enhancing fitness and other effects, which are regarded as treasures in both ancient and modern at home and abroad (Chen Sixing,1990). Especially in Japan, people are particularly fond of eels. Japanese eel festival would be held annually in late July, everyone must eat eel to celebrate that day. However, as the growing of people's demand for eel and the production of fishing eel begin to can't meet people's needs gradually. In addition, eel's resources become less and less because of overfishing. To solve the contradiction between eel's resources recession and huge market demand, eel aquaculture industry turns up and become more and more popular in the world, and the share of eel aquaculture production in the global eel production is becoming larger and larger. So far, there are no such researches about eel production trends change at home and abroad. Therefore, this paper tries to 1950 - 2012 eel production data analysis, systems analysis eel movements in global production, aquaculture production and catches, and to explore the main reason behind it, on this basis, the proposed policy recommendations to period government departments or related businesses to provide a reference.

In 2012, the global eel aquaculture production was a total of 241,285 Metric tons. The top six countries (regions) in eel aquaculture production was China, Japan, Korea, Taiwan, the Netherlands and Denmark, and the aquaculture production was 212,464 Metric tons, 17,377 Metric tons, 4,259 Metric tons, 2,244 Metric tons, 1,800 Metric tons and 1,061 Metric tons, which were accounting for the global the proportion of eel aquaculture production was 88.06%, 7.20%, 1.77%, 0.93%, 0.75%, 0.44% (Table 1). The sum yield of the eel aquaculture production of the top six countries accounted for 99.14% in the global eel aquaculture production. The first four countries' total eel aquaculture production accounted for 97.96% in global eel aquaculture production (Figure 1). Both of them indicated that a high oligopoly and a high degree of concentration in global eel aquaculture production market.

Table 1 Exports of Frozen Fishery Products of Pakistan (2012) Quantity Metric tons

Figure 1 Eel aquaculture production of the world's top six countries in 2012 (Unit: t)

Figure 2 shows that the global eel aquaculture producing countries (regions) are constantly changed with time in the history. Generally, it can be divided into two stages: the first stage is from 1950 to 1989, the global eel aquaculture is mainly concentrated in Japan and Taiwan; the second stage is from 1989 to 2012, the global eel aquaculture is mainly concentrated in China. In the history of global eel aquaculture industry, the maximum eel aquaculture production in Japan, China and Taiwan were 39,704 Metric tons (1989), 214,698 Metric tons (2009) and 55,816 Metric tons (1990). The largest share of eel aquaculture production in total global for Japan, China and Taiwan were 94.74% (1965), 52.41% (1988) and 88.06% (2012).

Figure 2 Eel aquaculture production Changing tendencies of the world's top six countries (1950-2012). Quantity Metric tons

Wu Chung, 2003.The competitiveness of the eel aquaculture in Taiwan, Japan, and China. Aquaculture,221 (2003) 115-124
http://dx.doi.org/10.1016/S0044-8486(03)00004-8